3bqd
From Proteopedia
Doubling the Size of the Glucocorticoid Receptor Ligand Binding Pocket by Deacylcortivazol
Structural highlights
Disease[GCR_HUMAN] Defects in NR3C1 are a cause of glucocorticoid resistance (GCRES) [MIM:138040]; also known as cortisol resistance. It is a hypertensive, hyperandrogenic disorder characterized by increased serum cortisol concentrations. Inheritance is autosomal dominant.[1] [2] [3] [4] [5] [NCOA1_HUMAN] Note=A chromosomal aberration involving NCOA1 is a cause of rhabdomyosarcoma. Translocation t(2;2)(q35;p23) with PAX3 generates the NCOA1-PAX3 oncogene consisting of the N-terminus part of PAX3 and the C-terminus part of NCOA1. The fusion protein acts as a transcriptional activator. Rhabdomyosarcoma is the most common soft tissue carcinoma in childhood, representing 5-8% of all malignancies in children. Function[GCR_HUMAN] Receptor for glucocorticoids (GC). Has a dual mode of action: as a transcription factor that binds to glucocorticoid response elements (GRE), both for nuclear and mitochondrial DNA, and as a modulator of other transcription factors. Affects inflammatory responses, cellular proliferation and differentiation in target tissues. Could act as a coactivator for STAT5-dependent transcription upon growth hormone (GH) stimulation and could reveal an essential role of hepatic GR in the control of body growth. Involved in chromatin remodeling. Plays a significant role in transactivation.[6] [NCOA1_HUMAN] Nuclear receptor coactivator that directly binds nuclear receptors and stimulates the transcriptional activities in a hormone-dependent fashion. Involved in the coactivation of different nuclear receptors, such as for steroids (PGR, GR and ER), retinoids (RXRs), thyroid hormone (TRs) and prostanoids (PPARs). Also involved in coactivation mediated by STAT3, STAT5A, STAT5B and STAT6 transcription factors. Displays histone acetyltransferase activity toward H3 and H4; the relevance of such activity remains however unclear. Plays a central role in creating multisubunit coactivator complexes that act via remodeling of chromatin, and possibly acts by participating in both chromatin remodeling and recruitment of general transcription factors. Required with NCOA2 to control energy balance between white and brown adipose tissues. Required for mediating steroid hormone response. Isoform 2 has a higher thyroid hormone-dependent transactivation activity than isoform 1 and isoform 3.[7] [8] [9] [10] [11] [12] [13] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA common feature of nuclear receptor ligand binding domains (LBD) is a helical sandwich fold that nests a ligand binding pocket within the bottom half of the domain. Here we report that the ligand pocket of glucocorticoid receptor (GR) can be continuously extended into the top half of the LBD by binding to deacylcortivazol (DAC), an extremely potent glucocorticoid. It has been puzzling for decades why DAC, which contains a phenylpyrazole replacement at the conserved 3-ketone of steroid hormones that are normally required for activation of their cognate receptors, is a potent GR activator. The crystal structure of the GR LBD bound to DAC and the fourth LXXLL motif of steroid receptor coactivator 1 reveals that the GR ligand binding pocket is expanded to a size of 1,070 A(3), effectively doubling the size of the GR dexamethasone-binding pocket of 540 A(3) and yet leaving the structure of the coactivator binding site intact. DAC occupies only approximately 50% of the space of the pocket but makes intricate interactions with the receptor around the phenylpyrazole group that accounts for the high-affinity binding of DAC. The dramatic expansion of the DAC-binding pocket thus highlights the conformational adaptability of GR to ligand binding. The new structure also allows docking of various nonsteroidal ligands that cannot be fitted into the previous structures, thus providing a new rational template for drug discovery of steroidal and nonsteroidal glucocorticoids that can be specifically designed to reach the unoccupied space of the expanded pocket. Doubling the size of the glucocorticoid receptor ligand binding pocket by deacylcortivazol.,Suino-Powell K, Xu Y, Zhang C, Tao YG, Tolbert WD, Simons SS Jr, Xu HE Mol Cell Biol. 2008 Mar;28(6):1915-23. Epub 2007 Dec 26. PMID:18160712[14] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Histone acetyltransferase | Human | Large Structures | Xu, H E | Acyltransferase | Alternative initiation | Alternative splicing | Charge clamp | Chromatin regulator | Chromosomal rearrangement | Coactivator | Cytoplasm | Deacylcortivazol | Dimer interface | Disease mutation | Dna-binding | Glucocorticoid receptor | Hormone binding pocket | Lipid-binding | Metal-binding | Nuclear receptor coactivator 1 isoform 1 | Nucleus | Phosphoprotein | Polymorphism | Protein binding | Proto-oncogene | Pseudohermaphroditism | Src1 | Steroid-binding | Transcription | Transcription regulation | Transferase | Ubl conjugation | Zinc | Zinc-finger
